1. Field of the Invention
The present invention relates to a drainage asphalt composite paving method for forming an impermeable drainage intermediate layer using a paving material including a non-solidifying rubberized asphalt with a single paving process, and a paving material composition including a non-solidifying rubberized asphalt used in the paving method, and more particularly to a paving method for providing a drainage pavement and an impermeable intermediate layer at the same time by using a paving material composition including the non-solidifying rubberized asphalt of the present invention to form a non-solidifying rubberized asphalt penetration layer in place of the intermediate layer of the conventional drainage pavement, and a paving material composition used in the paving method.
More specifically, the present invention relates to a road pavement method that involves applying a road pavement adhering to the underlying base layer to offer a waterproof performance, protect the base layer from penetration of water or moisture and prevent erosion of the road and adhering to the overlying surface layer to maintain the noise-reducing and draining performances, and more particularly to a drainage asphalt paving method and a paving material composition used in the paving method, where during the drainage asphalt paving process, the non-solidifying rubberized asphalt in the paving material melts down and moves upwards from the bottom of the drainage pavement to firmly bind with the overlying layer, thereby increasing the coupling force between the layers and enhancing the performances, such as acid resistance, alkali resistance, saline resistance, etc., to further increase the durability of the final pavement.
2. Description of Related Art
In general, the drainage asphalt road pavement consists of a surface layer, an intermediate layer and a base layer. The surface layer is made with a design of mixing proportion to have higher inter-aggregate porosity than the normal road pavements in order to ensure the more effective and rapid drainage in rich rainfall and the noise-reducing function.
However, the current drainage paving materials are poor in resistance to water or moisture, easy to tear or exfoliate due to low inter-aggregate coupling strength and often liable to get early damages with pore cave-in or clogging soon after the paving process.
Like this, the surface layer that is in direct contact with and exposure to the exterior may have the difficulty of achieving effective drainage and noise-reducing performances that are the most important functions of the drainage pavement, due to the use of a paving material not guaranteed in the quality.
Further, repairing a damaged drainage pavement by applying a second coating of the paving material costs higher than repairing general asphalt pavements and unnecessarily requires the process of laying an intermediate layer in the drainage pavement during the paving process. But, most of the drainage paving methods involves laying the surface layer right on the base layer, consistently causing damages of the surface layer.
As the prior art for solving this problem, Korea Laid-Open Patent No. 2012-0070153 discloses a noise-reducing drainage pavement and its paving method, which is contrived to solve the problem with the prior art. This prior art uses an emulsified asphalt as an adhesive resin (adhesive layer) material between the base layer and the surface layer to offer high permeability and good workability at room temperature with ease and convenience. But, the emulsified asphalt is inferior to the general asphalts in regards to the properties such as strength or elasticity and has the difficulty in increasing the adhesiveness and the adhering effect as an intermediate medium between the base layer and the surface layer with a defined range of the pavement thickness. Further, the emulsified asphalt displays low elasticity and high risk of brittleness at low temperature of 0° C. or below, so the adhesive layer is still liable to break by the load and impact transferred from the overlying surface layer.
The conventional cement concrete pavement is provided by a method of cutting the working region, applying an emulsion to the cut-off area and spreading an asphalt mixture for drainage surface layer. Such a method employs an emulsion in order to help binding two different materials like asphalt and concrete together. Like the above-mentioned emulsified asphalt, the emulsion displays low elasticity and high risk of brittleness at low temperature and has the inter-layer adhesive area easily to break to lose the water draining function in rich rainfall, allowing water to penetrate into the ground as well as the base layer, causing degradation of the cement concrete and ground subsidence and shortening the lifespan of the pavement.
On the other hand, the present invention makes the use of a non-solidifying rubberized asphalt layer as an intermediate layer that functions as a medium like a waist between the surface layer and the base layer and forms the non-solidifying rubberized asphalt layer as an impermeable layer in the form of an intermediate layer with a single paving process of forming the surface layer in an easy and simple manner, thereby increasing the adhesive strength with the underlying base layer and enhancing the coupling strength with the overlying aggregates beneath the surface layer.
In addition, such an impermeable layer in the form of an intermediate layer secures a perfect waterproofing function to fundamentally keep the water from penetrating into the underlying base layer from the drainage pavement, thereby preventing possible breaks or other damages caused by penetration of water.
Such a drainage pavement method is applicable to asphalt or cement road pavements. Advantageously, the non-solidifying rubberized asphalt used in the present invention can provide a simple solution to the problems possibly occurring in association with inappropriate choice and management of aggregates in the Japanese hybrid process and failed control in regards to the temperature and viscosity of the composition and the asphalt binder.
Further, by eliminating the process of forming an intermediate layer to a thickness of 4 to 5 cm as used in the conventional paving process, the present invention can decrease the height of the final pavement, reduce the incidental expenses for the paving materials and process and offer high elasticity and stretching performance peculiar to the non-solidifying rubberized asphalt used as the intermediate layer, resulting in a good effect of mitigating load and impacts transferred from top to bottom of the road and thus making it possible to install the road pavement with more safety and durability.